I’ve never had any problems with the Play Store on my Fire 7 or HD 8. Some apps don’t work, most annoyingly Google Inbox, and I’m sure all three people who use Google+ are disappointed it won’t work on the Fire, but in on the whole, it’s great. I’m Swype-typing this comment into Chrome on my HD 8 right now.
I was really happy to discover it’s now ridiculously easy to put Google on the Fire. It used to be you had to screw around with USB debug mode and ADB driver packages, but now you can add it from the Silk web browser. It made the recent sale on Fire tablets a heck of a bargain.